• Behavior: an action carried out by muscles under control of the nervous system
  • works via sensory pathway in nervous systems

• Behaviors have a genetic basis
  • allows for evolution by natural selection

• Learning connects experience and behavior
  • Genetics x Environment

• Q1. What stimulus elicits the behavior, and what physiological mechanisms bring about the response?

• Q2. How does the animal’s experience during growth and development influence the response?

• Q3. How does the behavior aid survival and reproduction?

• Q4. What is the behavior’s evolutionary history?

Take home message: Behaviors are not just a spontaneous reaction to a stimulus

• Q1: stimuli that trigger behavior…
  • Tinbergen kept fish tanks with stickleback fish
  • Males = red belly; Females= no red belly

• Male territorial behavior related to red color
  • males also behaved aggressively when a red truck passed by!

• Fixed Action Pattern:
  • developmentally ‘fixed’ → innate behavior
  • trigger = specific stimulus (i.e. red color)

• Environmental stimuli trigger and guide animal behaviors
  • for innate and learned behaviors

• Birds, fishes, mammals (+ more) use cues to migrate long distances
  • Why do animals not get lost in new habitats?

• Animals may use sun or moon position to navigate
  • adjust route with circadian clocks!

• Stimulus may come from other animals (Q1)

• Signal: a variety of mechanisms to communicate
  • male waving claw at female crab

• Communication: transmission and reception of signals
  • plays a role in primary cause (‘the How’)

• 4 common modes of animal communication
  • visual, chemical, tactile & auditory

• Step 1: Male sees female and orients towards her
  • uses olfactory chemical system to determine species

• Step 2: Male touches female with foreleg
  • alerts female to his presence

• Step 3: Male vibrate wing in courtship song
  • auditory behaviors shows female he is ‘fit’

• If all communications are successful → sexy time

• Many terrestrial mammals are nocturnal
  • use olfactory and auditory forms
  • usually are color blind

• Humans and most birds are diurnal
  • use visual and auditory forms
  • lack many olfactory cues

• The amount of information communicated varies
  • Bees communicate flower location using special dances. One bee dances, while other bees watch to learn the directions to a specific flower patch. The dancing bee smells like the flower patch, and also gives the watching bees a taste of the nectar she gathered. Smell and taste helps other bees find the correct flower patch.

• Learning: Modifications of behaviors as a result of experience

• Learning capacity → nervous system organization during development
  • genome encoded (behavior exists)

• Both nature (genes) vs nurture (environment)
  • finches can sing, but learn song from father

• Learning Types: Imprinting, Spatial, Associative, Cognitive, Social

• Q3: How does the behavior aid survival and reproduction?

• Food related behaviors: eating, searching, recognizing & capture
  • how did foraging behavior evolve?

• Fruit flies: variation in an foraging gene (for) dictates larval travel when foraging
  • for^R (rover) vs for^S (sitter)

• Which allele will be selected for in any population?

• Mate choice and mating behavior influence reproductive success

• Seeking, attracting & choosing mates are all under selection
  • mate competition

• Evolution of parental care produces more viable offspring
  • monogamy vs polygamy
  • certainty of paternity

• Mate choice behavior leads to sexual and intrasexual selection

• Behaviors have a genetic basis

• Courtship fruit fly: series of behaviors in male flies
  • single gene (flu) controls entire ritual
  • if flu mutated → no mating
  • variation in gene → variation in behavior
  • e.g., roles can be reversed in male and female!!!

• Variation in environment may cause behavior to evolve

• Behaviors should be mostly selfish
  • individual vs competitors

• Altruism:
  • sterile bees
  • animals that vocalize warning calls

• Can unselfishness arise through natural selection?
  • offspring survival: yours and relatives

• Inclusive fitness: increases genetic representation of related offspring